Guide vane having hooked fastener for a gas turbine

Abstract

A stator vane for a gas turbine includes a vane airfoil which extends in the longitudinal direction of the vane and which is delimited by a leading edge and a trailing edge, and also an outer platform, the inner side of which is exposed to the hot gas which flows through the gas turbine, and on which provision is made for a hook-like fastening element, projecting outwards in the region of the trailing edge, for fastening the stator vane on a casing of the gas turbine, which fastening element, on its side facing the trailing edge, has a locating slot above the trailing edge for the fixing of a heat shield which adjoins the outer platform of the stator vane in the flow direction of the hot gas. Provision is made on the outer platform of the stator vane between the locating slot and the trailing edge of a structure for reducing the thermal and mechanical stresses in the region of the transition between trailing edge and outer platform.

What is claimed is: 
     
       1. A stator vane for a gas turbine, which stator vane comprises:
 a vane airfoil which extends in a longitudinal direction of the stator vane and is delimited by a leading edge and a trailing edge; 
 an outer platform, an inner side of which is positioned for exposure to turbine gas, and on which at least one hook-like fastening element projects outwards in a region of the trailing edge; 
 at least one locating slot arranged above the trailing edge for fastening the stator vane on a casing or on an element of a gas turbine; 
 means for reducing thermal and mechanical stresses in a region of transition between the trailing edge and the outer platform, the means for reducing being located on the outer platform of the stator vane, between the locating slot and the trailing edge of the vane airfoil; and 
 wherein the trailing edge is set back in a turbine gas flow direction by a distance (a) in relation to the fastening element. 
 
     
     
       2. The stator vane as claimed in  claim 1 , wherein the locating slot is arranged above the means for reducing to fix a heat shield which adjoins the outer platform of the stator vane in a flow direction of turbine gas. 
     
     
       3. The stator vane as claimed in  claim 1 , wherein the means for reducing the thermal and mechanical stresses comprise:
 the outer platform having a reduced thickness in a region between the trailing edge and the locating slot. 
 
     
     
       4. The stator vane as claimed in  claim 3 , wherein the means for reducing the thermal and mechanical stresses comprise:
 a cavity introduced into the outer platform between locating slot and trailing edge at a location opposite a flow direction of turbine gas, wherein a progression of the cavity is formed substantially parallel to the inner side of the outer platform. 
 
     
     
       5. A gas turbine comprising:
 a stator vane having a vane airfoil which extends in a longitudinal direction of the stator vane and is delimited by a leading edge and a trailing edge; 
 an outer platform, an inner side of which is positioned for exposure to turbine gas of the gas turbine, and on which at least one hook-like fastening element projects outwards in a region of the trailing edge; 
 at least one locating slot arranged above the trailing edge for fastening the stator vane on a casing or on an element of the gas turbine; and 
 means for reducing thermal and mechanical stresses in a region of transition between the trailing edge and the outer platform, the means for reducing being located on the outer platform of the stator vane, between the locating slot and the trailing edge of the vane airfoil. 
 
     
     
       6. A method for providing sequential combustion, the method comprising:
 supplying a cooling medium to a gas turbine; and 
 producing hot gas which flows through the gas turbine, wherein a vane airfoil extends in a longitudinal direction of a stator vane of the gas turbine and is delimited by a leading edge and a trailing edge; 
 positioning an inner side of an outer platform for exposure to the hot gas of the gas turbine, at least one hook-like fastening element projecting outwards in a region of the trailing edge; 
 arranging at least one locating slot above the trailing edge for fastening the stator vane on a casing or on an element of the gas turbine; and 
 reducing thermal and mechanical stresses in a region of transition between the trailing edge and the outer platform, from a location on the outer platform of the stator vane, between the locating slot and the trailing edge of the vane airfoil.